The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Refrigeration and air conditioning systems generally include a compressor, a condenser, an expansion valve or its equivalent, and an evaporator. These components are coupled in sequence to define a continuous flow path. A working fluid typically called a refrigerant flows through the system and alternates between a liquid phase and a vapor or gaseous phase.
A variety of compressor types have been used in refrigeration systems, including, but not limited to, reciprocating compressors, screw compressors and rotary compressors. Rotary compressors can include both the vane type compressors, the scroll machines as well as other rotary styled compressors.
Scroll machines are becoming more and more popular for the compressor of choice in both refrigeration as well as air conditioning applications due primarily to their capability for extremely efficient operation. Scroll compressors are typically constructed using two scroll members with each scroll member having an end plate and a spiral wrap extending from the end plate. The spiral wraps are arranged in an opposing manner with the two spiral wraps being interfitted. The scroll members are mounted so that they may engage in relative orbiting motion with respect to each other. During this orbiting movement, the spiral wraps define a successive series of enclosed spaces, each of which progressively decreases in size as it moves inwardly from a radially outer position at a relatively low suction pressure to a central position at a relatively high discharge pressure. The compressed gas exits from the enclosed space at the central position through a discharge passage formed through the end plates of one of the scroll members.
An electric motor or another power source is provided which operates to drive one of the scroll members via a suitable drive shaft affixed to the motor rotor. In a hermetic compressor, the bottom of the hermetic shell normally contains an oil sump for lubricating and cooling the various components of the compressor.
Relative rotation between the two scroll members is typically controlled by an anti-rotation mechanism. One of the more popular anti-rotation mechanisms is an Oldham coupling, which is keyed to either the two scroll members or to one of the scroll members and a stationary component such as a bearing housing. While Oldham couplings are a popular choice, other anti-rotation mechanisms may also be utilized.
Due to the increasing popularity of scroll compressors, the continued development of these compressors has been directed towards designs that reduce size, reduce complexity and reduce cost without adversely affecting the performance of the scroll compressor.